3998999 has 2 divisors, whose sum is σ = 3999000. Its totient is φ = 3998998.

The previous prime is 3998993. The next prime is 3999001. The reversal of 3998999 is 9998993.

It is a happy number.

3998999 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 3998999 - 2⁴ = 3998983 is a prime.

Together with 3999001, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3998993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1999499 + 1999500.

It is an arithmetic number, because the mean of its divisors is an integer number (1999500).

Almost surely, 2^3998999 is an apocalyptic number.

3998999 is a deficient number, since it is larger than the sum of its proper divisors (1).

3998999 is an equidigital number, since it uses as much as digits as its factorization.

3998999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1417176, while the sum is 56.

The square root of 3998999 is about 1999.7497343418. The cubic root of 3998999 is about 158.7268625217.

The spelling of 3998999 in words is "three million, nine hundred ninety-eight thousand, nine hundred ninety-nine".